The first NASA crew to ride to the International Space Station on a commercial spacecraft may have to wait until at least the end of 2017, after NASA’s planning group realigned the US Crew Vehicle -1 (USCV-1) mission to a launch date of November 30, 2017. The new schedule includes the Russian Soyuz manifested as a back-up option, through to at least 2019.

All three companies have been reporting steady progress during the development phase, with Boeing the latest to make a positive announcement about their crew-capable spacecraft

Friday’s update noted they had successfully completed a Preliminary Design Review (PDR) on the Launch Vehicle Adapter (LVA) – the component that will be used to connect the CST-100 to the Atlas V’s Centuar Upper Stage.

The review is one of six performance milestones Boeing has completed for the CCiCap initiative, a process that totals 19 milestones under NASA’s $460m award. The company also completed the recently completed the Engineering Release (ER) 2.0 software review and the Landing and Recovery Ground Systems and Ground Communications design review.

“The PDR was an outstanding integrated effort by the Boeing, ULA and NASA teams,” said John Mulholland, vice president and program manager of Boeing Commercial Programs. “The ULA design leverages the heritage hardware of the Atlas V to integrate with the CST-100, setting the baseline for us to proceed to wind tunnel testing and the Launch Segment-level PDR in June.”

Should the test missions prove to be successful, a winning company will be selected by NASA to conduct the first crewed mission to the International Space Station – a mission known as US Crew Vehicle -1 (USCV-1).

The USCV-2 through to USCV-6 are shown to launch at intervals of six months, with a Russian Soyuz penciled in to provide a back up role “in the event the US Crewed Vehicle is unavailable” through to the USCV-4 mission in 2019.

The slip is not official and the FPIP presentation is a planning document, meaning its information is preliminary. However, like its Shuttle equivalent – the Flight Assignment Working Group (FAWG) documents (L2) – changes to the schedule always begin at this stage of planning, and almost always become the reality.

A confirmed delay to the USCV flights will impact the ISS in several ways, not least because the USCV missions will carry four crewmembers, meaning that once they dock to the ISS, the crew of the station will be boosted to seven – allowing significant extra research activities to be performed.

Notably, one of the crewmembers on the USCV will be Russian – just as one American crewmember will continue to be rotated on the Soyuz. This is done in order to ensure that a US crewmember is always present on the ISS, even when no USCV is docked to the station.

It is not known at this point whether the seat on the USCV will be provided to Russia in exchange for a US seat on the Soyuz.

(Images: L2 Content, SNC, ULA, Boeing)

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